1. Field of the Invention
The present invention is related to a portable communication device and network, and more particularly to a portable communication device and network and methods of operation thereof.
2. Description of the Related Art
Cellular telephones, messaging devices, PDAs (Personal Digital Assistants) and other portable communication devices have become fixtures of everyday life over the last several years. As they evolve, the devices' capabilities and differentiation have expanded. For example, such devices can be used to make wireless connection to the Internet, play games, send and receive videos and/or still pictures, carry out electronic mail and other messaging functions, as well as send and receive voice calls. It is anticipated that as time goes by, the capabilities and variety of such devices will continue to increase. For example, In the future, portable communication devices will have the capability to simultaneously operate in multiple modes such as communicating on a voice call while transmitting a large quantity of data.
The manner in which a portable communication device is utilized affects its radiated performance, which in turn affects the quality of service provided by the device. Each device can be operated in a different manner dependent upon the current operation being performed. For example, during a voice communication, a user positions the portable communication device against his/her head, aligning the device microphone with his/her mouth to facilitate speaking into the microphone, and aligning the device earpiece to his/her ear to facilitate listening to the output signal generated by the earpiece. As another example, when using a speaker, data transfer, or other hands free operation, the portable communication device is typically located at some greater distance from the user, perhaps resting on a table at a lower elevation. Further, variations in the local environment of the portable communication device affect its radiated performance. For example, when a device is located farther away from the base station, higher output power from the device may be necessary to communicate with the base station.
Communication devices must meet regulatory and industry-mandated standards. Regulatory agencies dictate the maximum amount of radiated power that a communication device can transmit in a designated frequency band, the maximum amount of radiated emissions that are allowed outside the operational frequency band, and also the allowable limits on Specific Absorption Rates or energy deposition. Industry standards follow the regulatory standards and also dictate the minimum allowable radiated levels for a given operational frequency band. In combination, these standards for communication devices constrain both the maximum and minimum power that a communication device can transmit, the maximum out of band radiated emissions, and the maximum levels of energy deposition.
The conflict between meeting regulatory and industry standards and providing optimum quality of service for a variety of communication functions within one portable communication device provides challenges to device designers. For example, for packet data protocols such as TDMA (time division multiple access), GPRS (General Packet Radio Service) and EGPRS (Enhanced GPRS), multiple uplink slots per frame are desirable in order to support the sending of large data files. An increase in the number of slots utilized can result in a corresponding increase in average transmit power, and this in turn can result in transmit power and heat dissipation levels not meeting desired quality of service levels. Today, these challenges are typically met using communication system-wide solutions.
The prevalence and expanded utilization of portable communication devices has led to a continually expanding variety of performance characteristics and capabilities. Such characteristics include antenna efficiency, heat dissipation, battery life, and the like. Today's system-level solutions do not allow for performance and functionality of each unique device to be optimized individually for individual operational modes.